Humans & Society

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During a total solar eclipse in 1919, Arthur Eddington and colleagues tested Einstein’s theory of gravity. Although the results showed Einstein’s theory was correct and Newton’s was wrong, Newton’s math was good enough to predict where the eclipse would be.

F.W. DYSON, A.S. EDDINGTON, C. DAVIDSON

A TANGLED SKEIN Splendid loops in the corona protrude from the sun’s surface, seen in this 2014 ultraviolet image from NASA’s Solar Dynamics Observatory. They are anchored in the sun’s messy magnetic field — so it’s a mystery how they stay so smooth.

NASA/Solar Dynamics Observatory

SIGNS OF LINES The sun’s magnetic field is connected to one in the corona, which is much weaker and therefore harder to observe. Together, they form a twisted mess, illustrated here as white lines (based partly on a model) over a 2016 image of the sun from NASA’s Solar Dynamics Observatory.